The present invention relates to a new and improved component of a coupling assembly which may function as either a clutch or a brake between a pair of elements and which dampens the transmission of vibration between the elements while transmitting force between the elements.
Known coupling assemblies which are used as either a clutch or a brake are disclosed in U.S. Pat. Nos. 2,203,862; 2,354,174; 2,418,099; 2,708,994; 4,552,257; and 4,958,713. Each of these known coupling assemblies has an annular base which is fixedly connected to one of two elements between which force is to be transmitted. An annular array of friction shoes is engageable with a friction surface connected with the other element. An annular fluid extensible tube is disposed between the base and the annular array of friction shoes.
When any one of these known coupling assemblies is used to transmit force between a pair of elements, vibration is also transmitted between the elements. To retard the transmission of vibration, a torsional coupling assembly has been connected in series with the coupling which functions as a brake or clutch. A typical torsional coupling assembly included an annular body of rubber disposed between and bonded to inner and outer metal housing sections. However, the provision of two coupling assemblies in a drive line increases the length of the drive line.
To reduce the length of the drive line, it has previously been suggested that the coupling assembly which functions as a clutch or brake and the torsional coupling assembly be combined. This was done by mounting a fluid extensible tube radially outwardly of a cylindrical metal band which extends around the outside of an annular body of rubber. A friction surface connected with the fluid extensible tube moves into engagement with the cylindrical metal band around the outside of the annular body of rubber when the tube is inflated. Heat generated by engagement of the friction shoe assemblies with the metal band can be readily transferred through the metal band to the annular body of rubber.